Rubber composition and method of preserving rubber



tion products of aldehydes and amines.

Patented July 21, 1931 STATE ATE? FF EE Iv'IARION C. REED, 0F CUYAHOGA FALLS, OHIO, ASSIGNOR TO THE B. F. GGODRICH CGIYL PANY, CF NEW YORK, N. L, A CORPORATION OF NEH] YORK RUBBER COIMPOSITION AND METHOD OF I PRESERVING RUBBER No Drawing. Application filed April 12, 1930. Serial No. 443,923.

This invention relates to the art of precontaining: blended plantation rubbers 100 serving rubber, either in the vulcanized or parts by weight, sulfur 5.5 parts, Zinc oxide unvulcanized condition, and to rubber com- 1: arts,*gasblacl parts, mineral rubber 10 positions so preserved. 7 parts, palm oil 5 parts, and hexamethylene it is well known that rubber is subject to tetramine 0.75 parts. This composition was more or less rapid deterioration upon aging, divided into two parts, one of which was especially when exposed to light, heat, or used as a control. To the other were added air. It has been proposed to treat rubber 0.95 parts of p,p diamino diphenyl ether with socalled anti-oxidants or age-reof the weight of the composition). sisters for the purpose of retarding its de- "lihe' compositions were thoroughly mixed, terioration and extending the period of its and vulcanized in a press for minutes at usefulness. Such previously known anti- 145 C. (294 F to produce an optimum oxidants include phenolic compounds, arocure. .The rate of aging of the vulcanized matic amino compounds, and the condensacompositions was determined by measuring their tensile strength and elongation before This invention consists in treating rubber and after aging. The accelerated aging tests with a member of a new class of ,age-rewere carried out in the Geer aging oven, in sisters, the said class comprising primary which samples were maintained ata temperaamino derivatives ofdiaryl ether-s. It inture of C. (158 F.) in a constantly recludes not only compounds containing one newed stream oi air, as well as in the Biereramino group, but also compounds contain-' Davis bomb, in which other samples were ing two or more primary amino groups. maintained at the same temperature (7 0 C.) Diaryl ethers containing an amino group on in an'atmosphere of oxygen at a pressure of each of the aromatic nuclei, such as p,p' 300 pounds per square inch. The results are diamino diphenyl ether, 0,0 diamino direcorded in the following table, in which T phenyl ether, m,m diamino di p-tolyl othe indicates ultimate tensile strength in pounds the diamino dinaphthyl ethers,.the diamino per square inch and indicates ultimate di-biphenyl ethers, etc. are particularly adelongation in percentoit original length: vantageous in the practice of this invention.

llo\vei ei, other compounds within the class defined above may likewise be employed. For example, 2, 1 diamino diphenyl ether, 3,5 diaminophenyl p-tolyl ether, p-amino phenyl naplnhyl ether, 0- amino pphenyl diphenyl ether, etc. are useful in the process of T E 'r E T E this invention.

It will be understood that the above-named me 0 630 1480 377 670 257 compounds are merely illustrative of the scope of the class, and that many other remg diphenyl lated compounds are likewise included Withn in the definition. Any one or a mixture of several of the above-mentioned class of ageresisters may be incorporated into rubber or a rubber composition with beneficial effects on its age-resisting properties v preferably Aging testsof 19,1) d'iamino diphenyl ether After 48 hours in the Bierer- Davis bomb After 7 days Before aging in the Geer oven Antioxidant Example 2.A rubber composition was prepared, containing essentially 15 parts by weight of rubber, 16. 15 parts of lithopone, 25 parts of inert pigments, 12 p arts of zinc oxide, from 0.2 to 5 parts by weight to parts of P r of Sulphur: Parts of an rubber being used organic accelerator. When this rubber com EwaW'Z Z)Z 1 A a ifi example f one position was vulcanized n air at 2 6Q F. for embodiment of the method of this invention, 2 rubber Was S0 b ly 0XlCl1Z ll that atypical tire tread composition was prepared the surface was extremely stlcky, while the tensile strength was only 765 pounds per square inch and the. elongation 583 per cent. WVhen 0.5 parts of diamino diphenyl ether were added and the rubber vulcanized in exactly the same manner, the vulcanized rubber had a dry surface and was very resilient and snappy, the tensile strength being 2666 pounds per square inch and the elongation per cent.

The compounds otthis class, in addition to their age-resisting properties, are mild accelu'ators and may be employed as such in rubber stocks which are to be vulcanized at high temperatures. However, they are particularly valuable as adjuncts to certain of the more active accelerators such as diphenyl guanidine, diothotolyl th'io'urea, and the aldehyde-amine reaction products, and particularly the sulphur-containing accelerators such as. mercapto benzothiazole, tetrame hyl thiuram monosulphide or disulphide, the dithiocarbamates, etc.

Obviously, the practice of this invention is not limited to the specific compositions given above, such compositions being merely illustrative of one manner of employing the age-resisters of this invention. T he proportions of the constituents may be varied, or other substances may be substituted therefor, since this invention is applicable to pure rubher or rubber compositions of the most varied nature. The age-resisters may also be applied to unvulcanized or vulcanized rubber with good effect on the age-resisting properties of the rubber, such as by applying them to the surface of the rubber, as for example in solution, or in the form of a paste or emulsion.

It is to be understood that the term treating as employed in the appended claims is used in a generic sense to include either the incorporation of t 1e age-resisters into the rubber by milling or similar process, or their addition to the rubber latex before its coagulation, or to the application thereof to the surface of a mass of crude or vulcanized rubber. T he term rubber is likewise employed in the claims in a generic sense to include caoutchouc, whether natural or synthetic, reclaimed rubber, balata, gutta percha, rubber isomers and like products, whether or not admixed with fillers, pigments, vulcanizing or accelerating agents.

While I have herein disclosed certain preferred manners of performing my invention, I do not thereby desire or intend to limit myself solely thereto, for, as hitherto stated, the

precise proportions of the materials utilized may be varied and other materials having -equivalent chemical'properties may be employed if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Iclaim:

1. The method of preserving rubber which comprises treating rubber with a primary amino derivative of a diaryl ether.

2. The method of preserving rubber which comprises treating rubber with a poly primary amino derivative 0% a diaryl ether.

3. The method of preserving rubber which comprises treating rubber with a diaryl ether containing a primary amino group substituted on each aryl group.

i. The method oi preserving rubber which comprises treating rubber with a diphenyl ether containing a primary amino group sub stit .ted on each phenyl group.

5. The method of preserving rubber which compris s treating rubber with p,p diamino diphenyl ether.

6,. The method of preserving rubber which comp 'ises vulcanizing rubber in the presence of diamino diaryl ether.

7. The method of preserving rubber which comprises vuleanizing a composition comprising rubber, sulphur, zinc oxide, an active organic accelerator of vulcanization, and a diamino diaryl ether.

8. A composi ion of matter comprising rubber and a primary amino derivative of a diaryl ether.

9. A composition of matter comprising 'ubber and a poly primary amino derivative of a diaryl ether.

10. A. composition of matter comprising rubber and a diaryl ether containing a pri mary amino group substituted on each aryl group.

ll. A composition of matter comprising rubber and a diphenyl ether containing a primary amino group substituted on each phenyl group.

12. A composition of matter comprising rubber and p,p diamino diphenyl ether.

, 13.. A composition or" matter comprising i rubber which has been vulcanized 1n the presence of a di amino diaryl ether.

1%. A composition of matter comprising rubber which has been vulcanized in the pres ence of sulphur, zinc oxide, an active organic accelerator of vulcanization, and a diamino' diphenyl ether.

In witness whereof I have hereunto set my hand this 31st day of March, 1930.

MARION C. REED. 

